Sounds outstanding. That isn't a lot more than what I paid used for my Limited Coupe, which was the same year and had a little more mileage on it. I CARFAX'ed mine and had two mechanics check it over before I bought it - which I'd recommend. I had been saving money for a Solstice (more in my price range) but couldn't deal with the lack of hardtop option - not practical for a high crime city. I liked the Crossfire more but considered it out of my price range. By getting it used I got a Crossfire for Solstice price. This SRT6 sounds like a steal. I hope it works out for you.

p.s. - also if you're getting it from a dealer, use some of what you're saving to spring for the 7 yr/70k warranty - it takes some of the nagging worry out of buying a used one.